Sources of Insoluble Fiber

by Melodie Anne Coffman

Whole-grain bread is a rich source of insoluble fiber.

Fiber is a necessary part of your diet, since it helps your intestinal tract push out waste from the foods you consume. It fills up your gut, which improves satiety and keeps you full for hours. Diets high in fiber also decrease your risk of heart disease because fiber helps your body excrete excess cholesterol in your blood. Fiber comes in two forms: soluble and insoluble. Many high-fiber foods contain both types of fiber, but most foods have higher amounts of one or the other. If you want to increase your insoluble fiber intake, choose foods that are high in this nutrient.

Soluble vs. Insoluble

Both soluble and insoluble fiber are important in your diet, and you need roughly equal amounts of both. Soluble fiber attracts fluid in your digestive tract and forms a slow-moving thick sludge. This substance slows digestion, which gives essential vitamins and minerals time to absorb through intestinal walls. Insoluble fiber stays relatively intact and sweeps through your digestive tract pushing out waste. This type of fiber adds bulk to your stools and makes bowel movements easier to pass. Parts of the food that are high in insoluble fiber often look the same in your stools, since insoluble fiber does not break down in your gut.

Recommended Intake

You need varying amounts of fiber, depending on age and gender. For every 1,000 calories you consume, you need 14 grams of fiber. Generally, women tend to consume fewer calories than men. Because of the varying caloric intake between genders, women need around 21 to 25 grams of fiber, while men need to get 30 to 38 grams, according to the Institute of Medicine.

Fruits and Vegetables

Insoluble fiber is the tough hard-to-chew part of grains and produce. For example, the soft inner part of apples is loaded with soluble fiber, but the outer skin that takes longer for you to chew is high in insoluble fiber. Salads include an array of veggies that contain insoluble fiber. Cabbage, lettuce, onions and bell peppers are loaded with this type of fiber. The outer husk of corn kernels is a rich source of insoluble fiber, as well as the skin of cucumbers, grapes and peas.

Grains

Whole-wheat flour, whole grains and wheat bran are chock-full of insoluble fiber. Read the nutrition facts label on your favorite type of bread or cereal. Ingredients on food labels are listed by weight. The term "whole grain" or "whole wheat" should be listed in the first few ingredients. This way you can be assured that the food you purchase is a good source of insoluble fiber.

Other Foods

Popcorn is an excellent source of insoluble fiber, but you should avoid piling butter on this popped snack. Adding high-fat butter packs excessive calories on popcorn, which is naturally low in calories. Dried fruits, including dates and prunes, are well-known for their role in relieving constipation. These foods are high in insoluble fiber and keep your bowels moving.

What's your dietary preference?

Gluten Free

Omnivore

Paleo

Vegetarian

Vegan

Which of these foods do you like to eat?

Fruit

Legumes

Meat & Poultry

Fish

Nuts & Seeds

Vegetables

Healthy fats

What kinds of foods would you like to incorporate more in your diet?

Healthy fats

Vegetables

Meat, Poultry & Fish

Grains

Fruits

Which of these fats do you like?

Olive oil

Avocados

Salmon

Olives

Sesame oil

Almonds

Which of these vegetables do you like?

Broccoli

Kale

Carrots

Peppers

Sweet potatoes

Which of these proteins do you like?

Beef

Chicken

Tilapia

Turkey

Eggs

Pork

Which of these grains do you like?

Whole wheat

Brown rice

Oatmeal

Cous Cous

Bulgar

Which of these fruits do you like?

Apples

Bananas

Pears

Kiwis

Oranges

Peaches

Pomegranates

Berries

Which of these foods do you like to eat?

Fish

Nuts

Vegetables

Meat & Poultry

Fruits

These are kinds of fish you can eat on a Paleo diet. Which do you like?

Halibut

Red Snapper

Tilapia

Salmon

These are some nuts you can eat on a Paleo diet. Which do you like?

Almonds

Cashews

Pistacios

Walnuts

These are some vegetables you can eat on a Paleo diet. Which do you like?

Broccoli

Peppers

Kale

Carrots

Lettuce

Cabbage

These are some proteins you can eat on a Paleo diet. Which do you like?

About the Author

Melodie Anne Coffman has been writing for various online and print publications since 1996, specializing in human and animal nutrition. After receiving her master's degree in food science and human nutrition, she opened up her own nutrition consulting business in the New England area.

Photo Credits

Whole grain toast served with butter. image by William Berry from Fotolia.com

Have Feedback?

Thank you for providing feedback to our Editorial staff on this article. Please fill in the following information so we can alert the Healthy Eating editorial team about a factual or typographical error in this story. All Fields are required.